Low density explosive



Patented Oct. 4, 1932 UNITED STATES PATENT OFFICE RAYMOND I. BASHFORD, OF PHILADELPHIILA, PENNSYLVANIA, ASSIGNOR, BYMFSNE ASSIGNMENTS, TO ATLAS POWDER COMPANY, A CORPORATION OF DELAWARE" Low DENSITY EXPLOSIVE N 0 Drawing.

My invention relates to a low density dynamite and material for use in conjunction therewith, and more particularly it relates to explosives of the ammonium nitrate type suitable for mining coal in gaseous mines.

One object of my invention is to provide an explosive of the permissible type containing ammonium nitrate, which explosive is relatively bulky, but at the same time highly sensitive.

A further object is to furnish an ammonium nitrate explosive, suitable for mining coal in gaseous mines in which a portion of the dense sodium nitrate is replaced by a relatively bulky, light, inert material.

Another object is to produce a material for use in ammonium nitrate explosives which is of low density and occupies a'r'elatively large space and which may be added to the ex plosive without reducing its sensitivity and without requiring oxygen during the explosion or detonation.

Still another object is to provide a method of treating inert material to render it suitable for use in ammonium nitrate explosives in conjunction with nitro-glycerine.

1 Other objects will be apparent from a consideration of the specification and claims.

The bulky ammonium nitrate low density explosives are to be desired in many instances, since there are more sticks per unit of weight and the explosive is distributed over a larger area in the bore hole than is the case with the standard explosives. Heretofore difiiculty has been encountered in making explosives of the bulky type of low strength, since in these explosives it has been found necessary to reduce the bulk as the strength is lowered'. In

the explosives of ie present invention it is possible to lower the strength of the explosive without appreciably decreasing the bulk or in any way affecting the sensitivity thereof.

One group of the explosives of the present invention has characteristics which satisfy the tests of the Bureau of Mines relating to Application filed Ianuary 23, 1932. Serial No. 588,503.

the so-called permissible explosives, and, therefore, it falls within that classification.

M invention contemplates the use of relatively bulky treated inert material to replace a portion of the sodium nitrate which not only is dense, but also requires additional amounts of carbonaceous material to satisfy its oxygen content. The inert material is treated to render it substantially non-absorptive toward nitro-glycerine, and, therefore, it is possible by its use to produce an explosive whose sensitiveness is not decreased. The inert material may be infusorial earth, known variously as kieselguhr, diatomaceous earth, fossil flour, etc., or finely divided or shredded asbestos, bulky in nature and light in weight,

or like materials which will not require oxygen in the explosion or detonation. The inert material-prior to its mixture in the explosive compound is treated by bringing it in contact with a solution, preferably one that L is saturated, of one or more salts which may or may not function in the explosion, but which do not render the explosive insensitive.

Preferably, the oxygen-bearing salts, capable of liberating oxygen during the explosion, are used in the explosive. Since the fumes which prevail upon explosion are such as will allow the explosive to pass the permissibility test, sodium chloride is an example of a nonoxygen-bearing salt which may be employed without rendering the explosive insensitive. The inert material absorbs the salt until the pores are substantially filled. Hence, the absorptive capacity is reduced to a olnt where no appreciable nitro-glycerine w1ll be absorbed when it is brought in contact wlth the treated material.

The inert material may be treated by mixing it with an approximately saturated solution of the salt, for example, sodium mtrate or ammonium nitrate, or a mixture of these oxygen-bearing salts, and allowing it to remain in contact therewith until practically complete absorption has taken place. The

material is then dried and screened free from lumps and is ready for compounding with the other materials which are to be used in making up theexplosive. The amount of salt absorbed by the inert material varies widely, and depends upon the nature and condition of the inert material. The treated inert material, for example, may have ab sorbed salt to an extent where the treated material comprises 20% to inertmaterial and 80% to 30% salt. The particular inert material being treated should have its absorptive capacity substantially satisfied by the salt, so that when it is brought in contact with the nitro-glycerine, it will take practically none of the compound into its pores.

The treated inert material when it contains an oxygen-bearing salt, as hereinbefore pointed out, is successful for use in conjunction with ammonium nitrate explosives of the permissible type. These explosives contain nitro-glycerine and sufficient carbonaceous material to satisfy the oxygen liberated from the oxygen-bearing salt during the explosion or detonation. The explosives usuall also contain sodium nitrate and an antacid and they ma or may not contain nitro-cotton. I

s typical of the explosives which may be used, the following example is given:

I r en! Ammonium nitrate 4 3 Nitro-glycerine 9-20 Sodium nitrate 10- 35 Carbonaeeous material Explosive without m'tm-cotton Percent Nitro-glycerine l2 Ammonium nitrate 40 Sodium nitrate 12.5 Carbonaceous material 14 Treated infusorial earth containing 25% ofinfusorial earth and 75% of sodium nitrate 20.5 Antarid (calcium carbonate) 1 "Explosive with nitro-cot ton Antacid (calcium carbonate) 1 Treated fine divided bulky asbestos containing 60% asbestos and 40% of sodium nitrate 9.25

The explosive of the present invention is a relatively bulky ammonium nitrate explosive low density which is highly sensitive, due to the fact that there is placed in the explosive a bulky inert material which is nonabsorptive toward the nitro-glycerine.

Considerable modification is possible in the choice of ingredients used in the formula, as well as in the proportions employed, without departing from the essential features of the invention.

I claim:

1. An ammonium nitrate low density explosive having therein a relatively bulky inert material, the pores of which are substantially filled with a salt.

2. An ammonium nitrate low density explosive having therein infusorial earth, the pores of which are substantially filled with a salt.

' 3. An ammonium nitrate low density ex plosive having therein finely divided relatively bulky asbestos, the pores of which are substantially filled with a salt.

4. An ammonium nitrate low density explosive having therein a relatively bulky inert material, the pores of which are substantially filled with an oxygen bearing salt capable of liberating its oxygen during the explosion.

5. An ammonium nitratelow d nsity explosive having therein infusorial gearth, the pores of which are substantially lled with .an oxygen bearing salt capable of liberating its oxygen during the explosion.

6. An ammonium nitrate low density explosive having therein finely divided relatively bulky asbestos, the pores of which are substantially filled with an oxygen bearing salt capable of liberating its oxygen during the explosion.

7. An ammonium nitrate low density explosive having therein a relatively bulky in- 1 ert material, the pores of which are substantially filled with sodium nitrate.

8. An ammonium nitrate low density explosive comprising ammonium nitrate, nitroglycerine, sodium nitrate, carbonaceous material sufiicient to satisfy the oxygen liberated from the oxygen bearing salts during the explosion, and relatively bulky inert material, the pores of which are substantially filled with an oxygen bearing salt capable of liberating its oxygen during the explosion.

9. An ammonium low density explosive comprising ammonium nitrate, nitro-glycerine, sodium nitrate, carbonaceous material sulficient to satisfy the oxygen liberated from the oxygen bearing salts during the explosion, and infusorial earth, the pores of which are substantially filled with an oxygen bearing salt capable of liberating its oxygen during the explosion.

10. An ammonium nitrate low density explosive, comprising ammonium nitrate, nitroglycerine, sodium nitrate, carbonaceous material sufiicient to satisfy the oxygen liberated from the oxygen bearing salts during the ex losion, and relatively bulky finely divided as estos, the pores of which are substantially filled with an oxygen bearing salt capable of liberating its oxygen during the explosion.

11. An ammonium nitrate low density explosive comprising nitro-glycerine between 9 per cent and 20 per cent; carbonaceous material between 6 per cent and 17 per cent; antacid between 0 per cent and 2 per cent; nitrocotton between 0 per cent and 1.5 per cent;

nitro-body between 0 per cent and 15 per cent; treated inert material between 4 per cent and per cent, said inert material containing between 20 per cent and 7 0 per cent of inert material and 80 per cent and per cent of oxygen bearing salt capable of liberating oxygen during the explosion; ammonium nitrate between 30 per cent and 75 per cent; and sodium nitrate between 10 per cent and per cent, the amounts of the two latter ingredients being independent of the amount of oxygen bearing salt carried by the inert material, the explosive being made up of the said ingredients to total 100 per cent.

12. An ammonium nitrate low density explosive comprising nitroglycerine approximately 12 per cent, carbonaceous material approximately 14 per cent, antacid approximately 1 per cent, treated inert material approximately 20.5 per cent, said inert material containing approximately 25 per cent of infusorial earth and 75 per cent of sodium nitrate; ammonium nitrate approximately per cent and sodium nitrate approximately 12.5 per cent, the amount of sodium nitrate being independent of the amount of sodium nitrate carried by the inert material; the explosive being made up of the said ingredients to total 100 per cent.

13. An ammonium nitrate low density explosive comprising nitroglycerine approximately 17 per cent, carbonaceous material approximately mately 1 per cent, treated inert material approximately 925 per cent, said inert material containing approximately per cent of finely divided bulky asbestos and 40 per cent of sodium nitrate; ammonium nitrate approximately 42 per cent, dinitrotoluene ap- 7.5 per cent, antacid approxiproximately 1 per cent, nitrocotton approximately .25 per cent, and sodium nitrate approximately 22 per cent, the amount of sodium nitrate being independent of the amount of sodium nitrate carried by the inert material; the explosive being made up of the said ingredients to total 100 er cent.

RAYMOND I. BASH ORD. 

